Concomitant Mitral Regurgitation in Patients Undergoing Surgical Aortic Valve Replacement for Aortic Stenosis: A Systematic Review.

Background: Concomitant mitral regurgitation (MR) is frequently seen in patients undergoing surgical aortic valve replacement (AVR) for severe aortic stenosis (AS). When the severity of MR is moderate or less, the decision to undertake simultaneous mitral valve intervention can be challenging. Methods: A systematic search of Medline, PubMed (NCBI), Embase and Cochrane Library was conducted to qualitatively assess the current evidence for concomitant mitral valve intervention for MR in patients with AS undergoing AVR. The primary outcome for this systematic review was the postoperative change in the severity of MR and other outcomes of interest included factors that predict improvement or persistence of MR and long-term impacts of residual MR. Results: A total of 17 studies were included. The percentage of patients demonstrating improvement in MR severity following AVR ranged from 17.2% to 72%; the studies that exclusively included patients with moderate functional MR and reported longer term echocardiographic follow-up of greater than 12 months demonstrated an improvement in MR severity of 45% to 72%. Conclusion: This systematic review demonstrates that a proportion of patients can exhibit an improvement in MR following isolated surgical AVR, but whether this confers any long-term morbidity and mortality benefit remains unclear.